MANUAL OB^ CATTLK-FEEDIXG, lOl 



For the sake of brevity, no description of tlie fodder lias 

 been given in any of the abo\ e evperiuients. It is suffi- 

 cient to say tliat it was found by experience to be just 

 sufficient to maintain the animals, and that the latter did 

 not appreciably gain or lose during the trials. The duration 

 of the feeding, vt^hen given, refers in most cases to the 

 total length of time during whieh the fodder was used ; 

 the actual investigation of dung and urine usually ex- 

 tended over 7 to 10 days. 



Investigations of the Respiratory Products. — The 

 experiments which we have already described have shown 

 conclusively that no appreciable excretion of nitrogen takes 

 place through lungs and skin, and direct investigations of 

 the respiratory products have only confirmed this fact. 

 It is time that we have no means of acciu*ately determining 

 how much free nitrogen is exhaled, but any ammonia that 

 may pass off in this way can be very exactly determined. 

 Such experiments have been executed, and have all shown 

 that only minute quantities of this gas are excreted. 

 Thus Grouven,* in experiments on twenty-nine different 

 individuals, obtained the followinfic amounts of ammonia 

 per 1,000 lbs. live weigl.t per day f 



Grms. Grms. 



Man 0.287-0.510 Sheep 0.340-0.585 



Boy.,,...,.. 0.457-0.541 Bog 0.663-1.850 



Ox 0.206-0,614 Horse 0.259 



€ow.. ....... 0.174-0.392 Ass 0.673 



Calf.... 774 Goat 0.585 



Hc^ 0,921 



Otlier observei-s have obtained equally small and unim- 

 portant amounts. 



Quite recently, Seegen and K"owak,t in Yienna, by a 



* Zwdter Salzmunder Berielit, 1S64, p. 235. 

 t Biedermaim's Central-Blatt, 1879, p. 593* 



